Google has released an iOS version of its free Translate app, and my first couple of hours of using it has shown it to be worth every penny.
Well, maybe a wee bit more than that, but I certainly wouldn't advise using it as the basis for any attempt at meaningful communication with someone with whom you share no linguistic common …

speak in your native language

The success of speech to text is strongly determined by your accent.

Using my iPad I got 100% success in English (British English being native tongue). And for Japanese, my wife's native tongue, she got perfect results on long and very technical sentences. However, vice versa was very dodgy though we speak each others' languages. So transliteration can work flawlessly, but only in certain circumstances.

Translation between Japanese and English was really rubbish every time.

Speaking the text results out loud was reasonably understandable for both languages.

Speaking as a translator...

...who makes use of google translate to look words up when I can't remember them, one thing to worry about is the implied assumption that there's a one-to-one correspondence between words in the source and target languages.

They only suggest one answer, when in fact there could be many answers, some subtly different, some very different in meaning.

It uses the cloud for its transactions

...and there's the rub. Usually you need a translator when you're abroad, i.e. roaming. Relying on this translator could therefore lead to some rather comical bills from your carrier, I'd have thought.

Hope it's better

When using my Android phone, my (American) wife had no problems with the voice recognition whereas my British (Herts-estruaryish) accent was never recognised, not for even a single word. I had no idea that even words like "search" and "phone" were so different. It worked fine whenever I used a terrible fake American accent though, even though it made everyone cringe, including me. I eventually changed the settings to British English and it has worked fine for me in my normal accent ever since.

They've all got dialects

"[I]ts Spanish-language capabilites proved to be superior to, say, its handling of Mandarin or Arabic – not to mention the fact that those latter two languages have vast numbers of regional dialects."

Since he is a native of San Francisco, I presume that the reporter, like the Google engineers, is most familiar with a generic Latin American Spanish which is taught in most US schools, and which is more or less intelligible to most of the Spanish-speaking world. There are regional differences, though, and Castilian Spanish (the variety dominant in Spain) is strikingly different from the Latin American varieties.

Similarly, if it has that much trouble with "standard" Japanese, I'd hate to see what happens when the app is confronted with, say, Osaka-ben. (Well, actually, maybe I'd really enjoy seeing what happens. But I wouldn't want to rely on it as a real-life translator.)